Amphibian propulsion mechanism



Patented July 23, 1946 2,404,488 AMPHIBIAN PROPULSIN ISM James M.v Hait, San Gabriel, Calif., assignor to Food Machinery Corporation, San Jose, Calif., a corporation of Delaware Application January 8,1942, seriarNo. 426,029

' This invention relates to amphibian'craft and particularly to track-laying devices for propelling the same both on water and on land. f

It is rcommon practice to employ for the propulsion of such craft track-laying devices which are similar tothose employed for propelling tractors and military tanks. These 'devices include endless` track-forming belts or chains which will be hereinafter referred to generically by use of the term beltf In modern warfare theV usefulness of amphibian craft would befgreatly enhanced ii these craft could be operated at high speeds on land. L

'Heretofore however it has beenl assumed to be necessary to equip the traction beltsof these craftl with metal blades or grousers to serve as impellers 'Y ficlaims, (o1. 1'15-1) Fig. is a side elevational-view of afmodiiied` form of the invention. I

Fig. 4 is a bottom' plan view of Fig. 3; I Referring specifically to the drawing, the pro-v pulsion mechanism I0 includes an endless belt II and aset of bogie wheels I2 provided on the amphibian equipped with this mechanisms.' Thebelt I I isk preferably formed o f rubber and steel and includes endless `steel cables vI3 an'dan when'the craft is traveling in the water and these blades werey not suitable toA allow the craft to travel at high speeds on land and particularly on hard-surfaced roads. Y.

It is an object of my invention to provide a propulsive mechanism of the track-laying type for an amphibian 'Craft which will provide an Y adequate propulsiva thrust when the craft is opl erated in the water and at. the same time willV be suitable for supporting the craft when the latter is operating on land lat relatively high` speeds withoutfthe'mechanism incurring any substantial damage due to this land travel.

In my laboratory experiments I have determined that to attain the maximum efliciency in impeller action each of said grousers must be relatively long in the direction in which these move with said belts. This renders it diilicult to mount the most eflicient type of grouser on the track-laying belts as the latter must make relatively short radius turns in passing around the idle and driving sprockets with which the belt is associated. v

It is another object of the invention therefore to provide such a propulsion mechanism which ticable.

will permit the use of grousers of Vhigh eiliciency and yet will facilitate these grousers readily pass-v ing around turns of short radii, thus adapting these grousers for use on track-forming belts.

Further objects and advantagesl will be made manifest inthe following description taken in of broken away as indicated by the line I-I in Fig. 2 to illustrate its construction. Fig. 2 is a bottom plan view of Fig. 1.

endless series of 5"steel clampsVV I4 Ywhich are clamped on the cables I3, these cables and clamps bethiheing imbedded in the rubber Vof thebelt I I. The bogie wheels I2k aref'formed so `that each bogie Wheel provides :a pair of rollers l5, the belt I I having articulating guide members I6 which'ex-` tend'upwardly betweenv the rolle-rs I5 of the bogie wheels I2 to hold the belt II inalignment withv the bogie wheels.

Clamps I4 are held togetherand tofthe bogi'e wheel guides I6 by bolts I1 and t8. The bolts- Il and I8 also serve torig'idly attach tothe belt Il, an endless series of grousersi25. Eachv of thesel grousers includes a pair of base plates26 preferably having downward iianged edges and bodies 210i: rubber which are bonded to .theses plates. Eachlof the plates 26 is attached to thebelt f'II by Aa set of'two bolts I'I andfa "centerbolt lilof one ofthe clampsjld. Theftvvof plates 26 of al acter to accommodate itself to this articulationl of the base plates 26 on which this rubber body is mounted. In this manner a kmuch longer grouser may be mounted on the belt I I to vfunction as a unit in engaging the water when the am# phibian is afloat than would otherwise be'pracgrousers of maximumefciency necessarily must be relatively longin the' direction' in which they travel on the belt II.

The rubber block 211s' shown-ias' moldednto embody animpeller blade 30 which not' only in-j.

corporates a highly eiicient form forY attacking the water but is of suilicient thickness to constitute an adequate cushion support for the belt II and the amphibian with which this ls equipped when'the latter is traveling Von land. It isto be noted that the blade 30 is symmetrical on oppo- Vsite'sides ofthe longitudinal axis of the belt II, Ytherimpeller on each side of this axis including a -relatively long substantially straight blade portion 3| 'which isinclined outwardly in they direction of its travel, thelatter beingindicated by This isof great consequence in thatV Whilek I regard the blade 30 to bea superior l It is believed clear that an amphibian equipped i with my invention would'notfonly, be able to travel at'relatively high speeds on land'and hardsurfaced roads and Vyet realize relatively high e'iciency in propulsive thrust from the trackforming belts when traveling through Water.

typerof grouser blade, from the standpoint of its 1 v l hydro dynamic elfciency, and because the reac s Y tionA forces producedby its travel through the Water are balanced onopposte sides of the axis Yof the belt so as to produce no side thrust, I do f` Y Vnot Wish the present invention to belimited ,tofv i the'use lof such a particular form of grouser blade.' 1 The'present invention particularly relatesto v the use of resilient means forforming a: grouser l so that one portion of this may articulate Vrelative toanother when the grouser passes around y 1 a turning axis thereby permitting `a relatively l long and eicient typeof grouserf bladeV to 'be i incorporated With the belt.

Y Referring'novvtofrl'igs. 3' and il, IhaveY here 1 thereof Vvvill'gy'ield?readily from any object enthe amphibian equipped with these grousers when' f While reference has 'beenV made herein to the" gr'ouser's'of my invention being formedof rubber,

Y this term. as: used in the claims Vis to beunderi stood( as generic inv scope and-as embracing not g only/What is technically'known as rubberybut 1 counteredthereby and is not depended upon. for any substantial contribution toward supporting w l the amphibian is traveling cn land. In the Water l however the grousers l'.' are adapted to operate Withk relativelyy high eiciency owing 'to their form.'4

all suitable substitutes therefor or Vequivalents thereof.

What I claim is: f

1 1. In an amphibian propulsion mechanism, the combination of: an endless traction belt; means for mounting said belt on said amphibian and driving the same; an endless series of grousers seeuredjitofsaid belt, each-of Ysaid grousers comprising 'af'bdy oi?J rubber andf'a plurality of atrtachingmeans for Aattaching said grouser to said belt, said attaching means being adapted to have articulating relation with each other when said belt travels around a turning axis. Y

-2. AIn an' Aamphibian propulsion mechanism, the

:combination of :"lanendless traction belt; means formounting saidk belt on said amphibian and' ,driving the same; anendless series lof grousers,

a substantial portion of each of which is formed ofy a' resilient material; and means for securing said grouser to said beltat points spaced in the direction of travel of said grouser on said'belt,

the'portions of said grousenat said points vof attachment being adapted to have flexing or articulating relation Withreach -other when belt rotates about a-turning axis. i l

3,. In an amphibian propulsion mechanism; thev combination ofi-an endless traction belt; means for mounting said belton. said lamphibian and drivingthe same; an endless. series of grousers provided on said belt, each of said grousers haviv ingva base secured to saidbeltand an impeller blade formed thereon,;said impeller blade-'3in1 cluding Va centrall ,cup-forming portion and'V outer blade portions dii/,erging symmetrically on. opposite sideso-f the. axis of said belt, the tipvportions ofV said bladesbeing formed Oirubber',

4,( 'InV an amphibian propulsionmechanism, thecombination tof; an endless traction belt; rneansy for mounting saidbelton lsaid amphibian andV driving the same; an endless.. series offgrousersv provided on said belt, each yoffsaicl grousers ,hav-

ing ,a basesecured tosaid belt andan impeller- Y blade .formedtherein, said impeller; :blade includ.

ing a centrall cup-forming: Yportion and vouter blade portions diverging symmetrically on oppositelsides of theaxisof. said ,belt,the tipzportions of ysaid ,blades beingvormed of rubber; andex-el tending beyond theborder line-'otV said base. i

'- Y :l .JAMES M. HAH'.Y

said 

